Fig. 3. ProIL2 preferentially localizes to and cleaves effectively in tumors.

a Equimolar doses of SumIL2-Fc or ProIL2 (300 pmol) was injected i.p. into CT26 s.c. tumor-bearing mice, and serum was collected and isolated at multiple time points. hIgG ELISA was used to quantify the amount of SumIL2-Fc or ProIL2 in the serum (n = 2 experiments, total 8 individual mice). b–h PBS or 200 pmol of SumIL2-Fc, ProIL2, or WTIL2-Fc was injected i.p. into CT26 s.c. tumor- or non-tumor-bearing mice, and the labeled tissues were collected and homogenized 24 h after treatment (n = 2 experiments, total 5 individual mice for PBS, 7 for SumIL2-Fc, 8 for ProIL2, 6 for WTIL2-Fc). b hIgG ELISA was used to quantify the amount ProIL2 in each homogenate, normalized by total tissue weight. c–f Cytometric Bead Array was used to quantify the amount of IFN or IL-6 in each tissue homogenate or serum. g, h hIgG immunoprecipitation of equivalent weights of tissue homogenate was performed with Protein A-binding beads, and then run on western blot with hIgG-binding antibody (n = 2 experiments, total 8 individual mice). g Relative gel band intensity per lane was quantified. h From each of the four tissues in one mouse, cleaved ProIL2 western blot bands were quantified relative to each other (i.e., the sum of cleaved ProIL2 bands from each of the four tissues = 100%). Data represent mean ± s.e.m. Mann-Whitney U tests were performed to calculate p values. Source data are provided as a Source Data file.